Lithium–sulfur (Li–S) batteries are regarded as the most promising next‐generation energy storage systems due to their high energy density and cost‐effectiveness. However, their practical applications are seriously hindered by several inevitable drawbacks, especially the shuttle effects of soluble lithium polysulfides (LiPSs) which lead to rapid capacity decay and short cycling lifespan. This review specifically concentrates on the shuttle path of LiPSs and their interaction with the corresponding cell components along the moving way, systematically retrospect the recent advances and strategies toward polysulfides diffusion suppression. Overall, the strategies for the shuttle effect inhibition can be classified into four parts, including capturing the LiPSs in the sulfur cathode, reducing the dissolution in electrolytes, blocking the shuttle channels by functional separators, and preventing the chemical reaction between LiPSs and Li metal anode. Herein, the fundamental aspect of Li–S batteries is introduced first to give an in‐deep understanding of the generation and shuttle effect of LiPSs. Then, the corresponding strategies toward LiPSs shuttle inhibition along the diffusion path are discussed step by step. Finally, general conclusions and perspectives for future research on shuttle issues and practical application of Li–S batteries are proposed.
Included
among the many challenges regarding renewable energy technology
are improved electrocatalysts for the oxygen evolution reaction (OER).
In this study, we report a novel bifunctional electrocatalyst based
on a highly dense CoO
x
catalyst by introducing
CeO
x
. The CoO
x
catalyst is fabricated by two-step electrodeposition, including
Co seed formation, to obtain a very dense, layered structure, and
CeO
x
is also successfully deposited on
the CoO
x
catalyst. CoO
x
is an active catalyst showing good activity (η = 0.331
V at 10 mA cm–2) and also stability for the OER.
Higher activity is observed with the CeO
x
/CoO
x
electrocatalyst (η = 0.313
V at 10 mA cm–2). From mechanistic studies conducted
with synchrotron-based photoemission electron spectroscopy and DFT
calculations, Ce promotes a synergistic effect by perturbing the electronic
structure of surface Co species (facile formation to CoOOH) on the
CoO
x
catalyst and optimizes the binding
energy of intermediate oxygenated adsorbates.
The microscopic process of oxidative etching of two-dimensional molybdenum disulfide (2D MoS2) at an atomic scale is investigated using a correlative TEM-etching study. MoS2 flakes on graphene TEM grids are precisely tracked and characterized by TEM before and after the oxidative etching. This allows us to determine the structural change with an atomic resolution on the edges of the domains, of well-oriented triangular pits and along the grain boundaries. We observe that the etching mostly starts from the open edges, grain boundaries and pre-existing atomic defects. A zigzag Mo edge is assigned as the dominant termination of the triangular pits, and profound terraces and grooves are observed on the etched edges. Based on the statistical TEM analysis, we reveal possible routes for the kinetics of the oxidative etching in 2D MoS2, which should also be applicable for other 2D transition metal dichalcogenide materials like MoSe2 and WS2.
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